Researchers from Tel Aviv have just discovered a new and easy attack on encryption: they listen to it. A computer’s processor emits a high-frequency sound while calculating an encryption. This sound varies characteristically due to the changing electrical current during the calculation. This way, the researchers were able to decrypt a 4,096-bit encryption key. Critics may now point out the fact that you would first have to be able to come close enough to listen to the computer. But this problem was solved eloquently. The researchers simply hacked the computer and took over the microphones. Modern-day PC microphones are good enough to pick up the electrical current modulating for a distance of about ten meters.